Piston for air compressors and gas engines



July 23, 1940. E. EICHELBERGER PISTON FOR AIR COMPRESSORS AND GAS ENGINES Filed April 20, 1937 ATTORNEY WITNESS Patented July 23, 1940 UNITED STATES- PISTON FOR AIR COMPRESSORS AND GAS ENGINES Edward Eichelberger, St. Louis, Mo.

Application April 20, 1937, Serial No. 138,015

3 Claims.

This invention relates to pistons for engines and compressors and has for the primary object the provision of a device of this character which will emciently operate in a cylinder to prevent loss of compression when the walls of the cylinder have worn to a maximum amount and have become egg-shaped or out of round and may be made to have a comparatively tight fit with the walls of the cylinder prior to the occurrence of wear.

Anotherobject of this invention is'the provision of a device of this character wherein the body thereof will have approximately the same life as the cylinder and which may-have the rings thereof removed and replaced when worn without removing the piston from the cylinder providing the latter has a removable head.

With these and other objects in view, this invention consists in certain novel features of. constructlon, combination and arrangement of parts to be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawing, in which Figure 1 is a side elevation illustrating a piston constructed in accordance with my invention.

Figure 2 is a sectional view taken on the line 22 of Figure 1. i

Figure 3 is a perspective view illustrating a removable head.

Figure 4 is a vertical sectional view illustrating a removable ring carrier.

Figure 5 is a perspective view illustrating one of the wear plates.

Referring in detail to the drawing, the numeral 1 indicates a body having the general shape of a piston and between its ends and upon its external face is cut away to form a shoulder 2 and tapering walls 3 which taper from the shoulder towards the closed end of the body, the closed end being indicated by the numeral 4. The tapering walls 3 and the shoulder 2 cooperate in forming a seat for an annular ring carrier 5 having a bore which tapers to match the tapered walls 3 of the body. The ring carrier 5 has formed .in its outer face spaced ring grooves 6 to receive the usual type of piston rings. The ring carrier 5 adjacent its lower edge is provided with a series of ports 1 extending through the lowermost ring groove and the inner walls of the carrier for the purpose of passing lubricant back through the piston to the usual crank case or lubricating reservoir or compressor in which the piston is employed. The ring carrier 5 when adapted'to at an angle to each other will aid in preventing the body projects a limited distance beyond the closed end of the body and detachably secured to the closed end t is a retaining head ll grooved to receive the projecting edge of the ring carrier and has formed therein converging openings Q 5 to receive stud boltslu which thread into converging screw threaded sockets formed in the end wall 6 of the body. The stud bolts may be locked in any well known manner and being set 10 the stud bolts from working out during the use of the piston.

The body i has the usual wrist pin opening and also has grooves or seats it formed on its exterior face and is further provided with grooves i2 positioned above and below the seats H. Wear plates i3 having lubricating openings it are oilset inwardly to form combined pivot and thrust bearings l5 to fit the seats H and they are provided with inturned flanges it at the ends thereof to fit in the grooves II. The wear plates It are constructed to conform to the contour of the walls of the body i and are capable of a limited rocking movement on the body. The wear plates may have slots ll extending inwardly from opposite edges to the bearings l5.

The wear plates and the rings carried by ring carrier contact the walls of a cylinder during the reciprocation of the piston in the cylinder. Therefore, the body and the ring carrier receive no wearand will have a life equal to the life of the cylinder. The wear plates may be constructed of a fibrous material or any other material suitable for the purpose and these wear plates fitting the walls of the cylinder will aid in removing piston slap and will receive the major portion of the wear, therefore, relieving the walls of the cylinder of excessive wear. These wear plates can be easily replaced by others when worn.

It is here noted that the recessed seats II in the opposite sides of the piston body are located in different planes, one being approximately in the plane of the axis of the wrist pin bearing opening and the other in a lower plane, and the relative shorter and longer distances between the 45 seat I I and the upper and lower correlated grooves I! at one side of the piston body being the same as the corresponding distances between the seat II and grooves I! at the oppposite side thereof but in reverse order and that the plates .50 I3 are accordingly formed and proportioned so as to be usable interchangeably on either side of the piston body but, of course, in reversed placement. The provision fod limited pivotal movement of the wear plates l3 and the particular staggered relation of the seating portions I l in which the pivot and thrust bearing portions l5 of the wear platesare received is to more effectively overcome piston slap and assure a more nearly straight longitudinal travel of the piston in the cylinder, which advantage is also due to the provision for limited rocking movement of the wear plates as well as in the particular staggered relation of the seats II and interfitting portions l5 of the plates. It is further pointed out that while the apertures I4 in the wear plates l3 are intended primarily for the purpose of lubrication they have an equally important function in serving as relief openingsror bleeders to prevent pocketing of oil or air between the body portions of the plates and the adjacent circumferential portions of the piston body which would otherwise interfere with or prevent the rocking of the plates, which is an essential feature of the invention, in that such rocking movement efiectively compensates for wear in the opposed cylinder wall portions and thereby'practically prevents piston slap and assures the more direct longitudinal movement of the piston as hereinabove set forth.

The ring carrier 5 projecting slightly beyond the closed end 4 of the body will permit a person with the use of a suitable tool to easily obtain a grip on said ring carrier for the purpose of pulling the same off of the body after the removal of the retaining head 8. Cylinders which have removable heads will expose the upper end of the piston when the cylinder head is removed, consequently a person can, after the removal of the retaining head 8, easily remove the ring car- I rier and the rings therewith and if the rings are found to be worn they can be replaced by others. After the renewal of the rings on the carrier the latter is replaced on the body and the retaining head 8 again secured in position on the body. Thus it will be seen that it is possible and very convenient to remove and reapply rings on a piston without removing the piston from the cylinder which provides for a large saving in time and expense in that the customary practice of removing crank cases and connecting rods to withdraw pistons from the cylinder is eliminated. The body I has a series of ports I8 .to align with the ports of the ring carrier.

What is claimed is:

' l. A-piston comprising a body having the general shape of a piston including a closed end, seats formed on the outer face of the body and the latter having grooves with the seats arrangedtherebetween, wear plates curved to conform to the contour of the body and offset intermediate the ends thereof to form bearings engageable with said seats to permit rocking of the wear plates on the body, flanges formed on the ends of said wear plates and extending into the on the body.

2. A piston comprising a body having an annular skirt portion formed with circumferential recesses on opposite sides thereof, said recesses being concaved transversely and extending with limited length annularly of the skirt portion, and parallel grooves above and below said recesses of greater length and extending equally beyond the opposite ends of said recesses, and arcuate wear plates conforming to the circumference of the skirt portion of the piston, said plates having inwardly offset counterpart combined pivot and grooves for limiting the rocking of the wear plates thrust bearing portions received in the circumferential recesses of the skirt portion of the piston and intumed marginal flanges received i'n said parallel grooves of the skirt portion of' the piston, said wear plates being apertured for lubrication and the escape of fluid from between the plates and the adjacent circumferential portion of the piston body.

3. A piston comprising a body having an annu.

lar skirt portion formed with circumferential recesses in different planes on opposite sides thereof, said recesses extending with limited length annularly of the skirt portion, and parallel grooves above and below said recesses of greater length and extending equally beyond the opposite ends of said recesses, the upper grooves being in a common plane and the lower grooves also combined pivot and thrust bearing portions correspondingly located between the flanged end portions of the plates and received in the recesses of the skirt portion of the piston, said wear plates being proportioned as to the relative dis tances between the flanged end portions and the intermediate oiiset bearing portions whereby the plates are reversible and applied interchangeably on either side-of the piston.

EDWARD EICHELBERGER. 

